The ordered micro-domain in Ba1-xSrxTiO3 thin films and its effect on phase transition

Ba0.7Sr0.3TiO3 (BST) thin film with 500 nm in thickness was deposited onto Pt/Ti/SiO2/Si(100) substrates by sol-gel method. The gold dot matrix with 0.5 mm in diameter was sputtered onto the film as upper electrodes, and MIM structure capacitors were formed. The thin films, as evidenced by transmission electron microscopy, exhibit the 1/2{201} ordered microdomains. In addition, the films show diffuse phase transition, as could be seen from the dependence of dielectric permittivity and polarization hysteresis on temperature, which were different from those of corresponding bulks.